Sounds like a fun trip in the making.
$25k will require some thrifty shopping. I'd concentrate on finding the best deal with enough room vs a particular type of RV.
No experience rv mean not experienced towing? In that case I'd be thinking A or C.
If you get a trailer, unless it's too hot, I personally wouldn't have issue with the pets riding in it. Some do, it certainly isn't too rough. No AC though unless you run onboard generator. AC runs on AC.
If towing, make sure the vehicle you tow is towable without removing the driveshaft.
